1. Field of the Invention
The present invention relates to a mobile communication system, and more particularly to a data communication method for a mobile communication system.
2. Description of the Related Art
FIG. 1 is a view illustrating a schematic diagram of a conventional mobile communication system. Referring to FIG. 1, mobile stations (MSs) 110 and 112 are connected to a BTS (Base Transmit Subsystem) 120 over an air interface, and a MS 114 is connected to a BTS 122 over the air interface. The BTSs 120 and 122 are wirelessly connected to the MSs 110 and 112, and the other BTS 122 is wirelessly connected to the MS 114. Upon receiving each incoming call for MSs of corresponding service areas from a BSC (Base Station Controller), the BTSs transmit the incoming call to a corresponding MS. Then, if the MS transmits an outgoing call to the BTS, the BTS transmits the outgoing call to the BSC 130. The BSC 130 manages the overall call control processes such as a voice call process, circuit call process, and packet call process, etc., of each MS. Also, the BSC 130 performs signaling with a MSC (Mobile Switching Center), and performs a handover operation.
The MSC 140 is connected to a HLR (Home Location Register) 150. The MSC 140 performs a call connection/switching function for processing incoming/outgoing request signals entering the MSs 110, 112 and 114, and performs a network-interworking function with other MSCs. HLR (Home Location Register) 150 is a database for storing/managing data of mobile phone subscribers. The HLR 150 registers or deletes a subscriber's location, and inquires about subscriber information.
Multiple-access wireless communication between the BTSs 120 and 122 and the MSs 110, 112, and 114 in such a mobile communication system is established over RF (Radio Frequency) channels for providing the mobile communication system with physical paths to transmit a plurality of communication signals such as an audio signal, a data signal, and an image signal, etc. Uplink channels, indicated as dotted lines in FIG. 1, are adapted to establish a call connection state among the BTSs 120 and 122 and the MSs 110, 112 and 114 or adapted to answer a message received from a paging channel. The downlink channel, indicated as solid lines in FIG. 1, is adapted to transmit voice or data signal information to the prescribed MSs 110, 112 and 114 at the BTSs 120 and 122. That is, one wireless channel is composed of one uplink channel and one downlink channel.
For instance, in the case where two MSs 110 and 112 connected to the BTS 120 are interconnected to each other such that data is interchangeable between the MSs 110 and 112 over the BTS 120, one wireless channel composed of one uplink channel and one downlink channel is assigned between the MS 110 and the BTS 120, and the other wireless channel is assigned between the MS 112 and the BTS 120. In conclusion, two uplink channels and two downlink channels are used between the MSs 110 and 112 to establish data communication between the MSs 110 and 112.
The aforementioned connection scheme for the conventional mobile communication system is indispensable for a full-duplex connection requiring two-way simultaneous data transmission. However, if only one-way data transmission is required at a prescribed time, for example, if one MS sends a file to a counterpart MS in the range of short distance (i.e., within a service area of one BTS), two-way channels assigned each MS are adapted to interchange signaling command/response messages for establishing a wireless access state with others, but there is little traffic on such two-way channels, resulting in unnecessary consumption of most of channel capacities.